Respirators of the type indicated above are housed in stand-by containers which can be closed airtight and are used, for example, by miners who carry them constantly on their bodies. The device is removed from the stand-by container for use.
In a known respirator of the general type depicted here, the respirator bag is located above the chemical cartridge, and the cartridge is placed in the lower part of the housing; the respirator bag with its breathing hose and mouthpiece are located in the upper housing cover. The respirator, together with its stand-by container must be worn on the body by means of a shoulder strap.
With such a breathing apparatus, (where the respirator bag is carried in front of the chest), the temperature increases during breathing because of the sensible heat of reaction from conversion of the contained oxygen-producing chemical.
The management of the surface temperature of the chemical canister is vitally important for the reason that during the breathing transient, short-duration temperatures as high as 250.degree. C. can be reached. The buildup of temperature between the back surface of the respirator and the abutting chest of the user of the device can cause inflammation and other skin irritations, which are a plainly unacceptable side effect. It almost goes without saying that such risks must be controlled in order that the user does not burn himself as a side effect. One solution to reducing this risk is described in Austrian Pat. No. 87,667, Sept. 15, 1921.
British Pat. 1,170,702 to Drager, teaches a portable respiratory apparatus. The apparatus is worn on the back of a user and includes a chemical container that processes exhaled breath into oxygen, a breathing bag and an oxygen bottle. A second container situated between the first container and the user holds coolant which cools the first container. In addition there are tubes which extend down from the second container along the back of the user that allows the coolant to flow through to provide further cooling. The above mentioned components are supported and positioned in a carrying structure.
Additionally, Drager teaches an apparatus that is used constantly over long periods of time rather than emergency situations that are short in comparison and is not collapsible to conveniently fit on the belt of the user and be worn until it is needed. Drager teaches the use of tubes to supply connection means that feed the coolant across the back of the user. The material around the tubes assists or increases the cooling effects from the coolant tubes. Unfortunately, if heat were present in the Drager apparatus, the material would increase the distribution of it.
Accordingly, it is an object of the invention to provide a respirator device where the ambient temperature is reduced substantially between respirator surface and the chest of the carrier by means of a space-saving device.